This invention relates to couplings for connecting water closet drains to sewer pipes, and more particularly, it relates to a mounting ring which secures the coupling to a water closet and to an adjacent floor when desired.
In recent years plastic water closet couplings have been used to connect the drains of water closets to sewer pipes. These water closet couplings are normally made out of plastic materials such as PVC and ABS. Generally speaking water closet couplings comprise a connecting pipe which is solvent bonded onto the sewer pipe, an extension toward the water closet forming a flange with a radially extending channel near the inlet end of the coupling and a mounting ring retained within the channel. These water closet couplings are normally sold as a single unit which is referred to as a closet flange.
The mounting ring normally has holes in it which enable it to be fastened to the floor, thereby securing the coupling to the floor. The mounting ring also normally has arcuate slots formed within it. After a wax ring is placed about the inlet end of the coupling, the drain of the water closet is set within the coupling so that a base portion of the water closet fits over the mounting ring. The base has holes in it with bolts mounted at positions within the base which enable heads of the bolts to extend through a widened portion of the arcuate slots of the mounting ring. The water closet is rotated slightly to fit the heads of the bolts under the mounting ring. The bolts, when tightened, thus fasten the water closet to the mounting ring and in turn to the floor. Assemblies of this type are shown in U.S. Pat. No. 3,319,268 issued on Mar. 16, 1967 to Blumenkranz and U.S. Pat. No. 3,775,780 issued on Dec. 4, 1973 to McEwen. One such assembly is shown in FIG. 1 and described below.
The load of the water closet is transmitted through the mounting ring. Thus, over a period of time after the installation of a water closet as described above, it is not unusual to find that the mounting ring breaks. This normally occurs in the vicinity of the arcuate slots, where the mounting ring is connected to the water closet. The mounting rings often break due to the stress from the water closet on the mounting ring in the area of the arcuate slots or due to rust or corrosion. As a result, the broken mounting ring has lost its seal and unsanitary liquid leaks from the water closet.
In the past, a number of different methods have been used to repair broken mounting rings. The most common practice has been to disconnect the water closet from the broken mounting ring and the rest of the closet flange and then remove and replace the existing closet flange. Since the existing closet flange has normally been solvent-bonded to the sewer pipe for installation and sanitary purposes, the sewer pipe is often cut at the level where the existing closet flange ends. This is an effort which can be difficult and time-consuming. It sometimes can involve tearing out and replacing portions of the floor beneath the water closet or in some cases even a ceiling below the water closet.
As a result, there have been a number of developments attempting to repair broken mounting rings, rather than replacing them. The patents relating to these developments include U.S. Pat. No. 4,207,630 issued on Jun. 17, 1980 to Bressler which discloses the use of a spanner clamp or flange which extends beneath and support the portion of the mounting ring which has failed. However, since this spanner flange is an extra member which is not an integral portion of the mounting ring, it is subject to potential displacement from the position in which it is mounted. The original problem would then reoccur.
An anchoring device and method for anchoring a toilet to a broken water closet ring are described in U.S. Pat. No. 5,220,694 issued Jun. 22, 1993, to Knorovsky. The anchoring device includes two arcuate members which can be positioned about a broken mounting ring, with their flat surfaces located directly beneath a radial plane of ring. The ends of the radial members are secured together to support the damaged mounting ring. However, the mounting ring can continue to deteriorate until the anchoring device itself can fall off.
Additionally, U.S. Pat. No. 5,492,372 issued on Feb. 20, 1996 to Dranberg, has proposed to replace the original mounting ring with a replacement ring comprising two arcuate pieces. Starting at column 3, line 13, the Dranberg patent contrasts the U-shaped profile of the original mounting ring with two generally flat arcuate pieces it discloses as a replacement.
The replacement ring described in the Dranberg patent is shown in FIG. 2. Each arcuate piece 10 has a stepped-up end 11 which overlaps a flat end 12 of the other piece to enable the pieces 10 to be connected together by fasteners 13. Four holes 14 are included in the arcuate pieces 10 to enable the replacement ring to be fastened to the floor near a water closet. Each arcuate piece 10 also has a stepped-up section 15 having a slot 16 in it to accommodate a bolt or other connection of the replacement ring to a water closet. At these four stepped-up areas the strength of the wax seal placed upon the ring is potentially compromised since there is a discontinuity in the surface of the replacement ring leading to them.
As seen in FIG. 2, inner edges 16 of the stepped-up overlapping ends 11 and inner edges 17 of the stepped up sections 15 are offset from the balance of the arcuate pieces 10 shown in the Dranberg Patent to enable the inner edges of the balance of the arcuate pieces to engage the channel in the closet flange. Thus, while the total circumference of the original mounting ring contacted the channel of the closet flange, a smaller portion of the circumference of the Dranberg patent's replacement ring contacts that channel. This decreases the strength and rigidity of the attachment of the ring to the closet flange. Additionally, by having a flat cross section rather than the U-shaped cross section of the original ring, the replacement ring does not have the additional strength and stability obtained from a channel-shaped cross section.
There is a closet flange currently being manufactured and sold which is molded in total as a single piece of plastic material. That is, that closet flange does not have a separate mounting ring installed on it. Rather, the flange portion of the closet flange is extended radially a distance sufficient to include the arcuate slots required to attach a water closet to it and to include the holes in it to be used to fasten the closet flange to the floor. Thus, if the extended flange portion of this closet flange is broken, it normally cannot be readily repaired because the plastic extended flange is integral with the rest of the closet flange. The replacement ring shown in U.S. Pat. No. 5,492,372 cannot be installed on it.